JPH0493291A - Thermal stencil paper and preparation thereof - Google Patents

Abstract

PURPOSE:To accurately carry out perforation by impregnating a porous support with a thermoplastic resin. CONSTITUTION:A porous support 1 is impregnated with a thermoplastic resin 2 and a resin absorbing body 3 substantially having heat resistance such as a foamed resin film layer or tissue paper is superposed on one surface of the support 1 and, when the obtained laminate is imagewise heated on the side of the support by a heating means 4 such as a thermal head, the resin 2 in the support 1 is melted to be absorbed in the resin absorbing body 3 and a perforation 5 is formed without leaving the molten resin in the support 1. As the porous support, tissue paper composed of a natural fiber having a fiber diameter of 0.1-30mum such as cotton, a paper mulberry fiber, a paper brush fiber or a rayon fiber, paper composed of a mixture of a natural fiber and synthetic fiber and a mesh sheet or reticulated resin sheet composed of polyester or polyamide are designated. As the thermoplastic resin, a low-molecular resin having a low softening point and low melt viscosity is pref. and, especially, synthetic or natural latex of every kind is suitable.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a thermal mimeograph base paper and a plate-making method thereof, and more particularly to a heat-sensitive mimeograph base paper and a plate-making method thereof that allow high-quality printed matter to be obtained.

(Prior art and its problems) In the past, the mimeograph printing method has been widely used as a simple printing method, and in this method, a thermoplastic resin film is laminated on the surface of a suitable porous support such as paper. Printing is performed using a thermal head, etc., and the thermoplastic resin film is heated and melted to form perforations in the form of an image, and printing is performed on a printing material such as paper by passing printing ink from the porous support side. be.

When making a plate from the above-mentioned base paper, if the base paper has insufficient smoothness, cushioning properties, etc., there is a problem that poor contact between the thermal head and the thermoplastic resin film will occur, and accurate perforations will not be formed. In order to solve these problems, various methods have been proposed to increase the smoothness of the support, but since the support is porous, there is a limit to smoothing it, and the base paper is thin to a certain extent. Since this is required, there is a limit to the cushioning properties, and the above problem has not been fully solved.

In addition, conventional base paper is perforated by thermally melting the thermoplastic resin film layer and shrinking the film layer, but at that time, there is no place for the molten resin to escape, and the resin that has been melted and solidified once forms the support. There is a problem that it gets tangled with fibers and reduces the resolution of printed matter. For this reason, it is preferable to use a film layer as thin as possible, but extremely thin film layers are extremely difficult to manufacture and handle.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the problems of the prior art as described above, and to provide a thermal mimeograph base paper and a plate-making method thereof that provide excellent high-quality printed matter.

(Means for solving problems) The above objects are achieved by the present invention as described below.

That is, the present invention provides a heat-sensitive mimeograph base paper characterized by having a porous support impregnated with a thermoplastic resin, a resin absorbent layer overlaid on one side of the base paper, and a resin absorbent layer on the other side of the base paper. This is a method for making a plate for thermal mimeograph base paper, which is characterized in that the impregnated resin is melted by selectively heating it in an imagewise manner, and the molten resin is absorbed into a resin absorber.

(Function) Instead of laminating a thermoplastic resin film layer on a porous support, by impregnating the support with a thermoplastic resin, it is possible to provide a heat-sensitive mimeograph base paper that provides high-quality printed matter.

Furthermore, according to the method of the present invention, most of the molten resin is absorbed by the resin absorber, so that only a small proportion remains on the support, thus making it possible to drill holes accurately.

(Preferred Embodiments) Next, the present invention will be described in more detail by citing preferred embodiments.

The thermal mimeograph base paper of the present invention has a porous support 1 impregnated with a thermoplastic resin 2 as shown in the first diagram, and preferably has a relatively heat-resistant foamed resin film layer on one side thereof. When resin absorbers 3 such as tissue paper are stacked and heated from the opposite side in an imagewise manner by a heating means 4 such as a thermal head, the resin 2 in the support is melted and absorbed by the resin absorber 3, and the molten resin is supported. without remaining in the body 1 (a perforation 5 is formed).

The porous support used in the base paper of the present invention as described above may be any conventionally known porous support (with a fiber diameter of 0.1
Thin paper made of natural fibers such as ~30 μm cotton, paper mulberry, Japanese mulberry, Manila hemp, flax, straw, bagasse, etc.; made of natural fibers such as polyester fiber, vinylon fiber, acrylic fiber, polyethylene fiber, polypropylene fiber, polyamide fiber, rayon fiber, etc. Thin paper or mixed paper made of a mixture of these natural fibers and synthetic fibers, 100-400
Examples include mesh sheets made of mesh or higher polyester, polyamide, etc., mesh-like resin sheets, and the like.

The basis weight of these supports is in the range of 6.0 to 14.0 g/rrr, and the porosity is arbitrary 45 μm x 85 μm in plan view.
It is preferable that it is 20% or more at the corners.

As the thermoplastic resin to be impregnated into the porous support, for example, polyvinyl chloride, vinyl chloride-vinylidene chloride copolymer, polyolefin such as polyester, polyethylene, polypropylene, polystyrene, etc. can be used, but the melt viscosity is Therefore, absorption into the resin absorbent body may not be sufficient. Therefore, preferred resins are low molecular weight resins with a lower softening point (and lower melt viscosity), and various synthetic waxes and natural waxes are particularly suitable.

Representative examples of wax include microcrystalline wax, carnauba wax, paraffin wax, and the like. Furthermore, various waxes such as Fischer Trobuchet wax, various low molecular weight polyethylenes, wood wax, beeswax, spermaceti wax, privet wax, wool wax, shellac wax, candelilla wax, petrolactam, -daily wax, fatty acid ester, fatty acid amide, etc. can be mentioned.

However, since the above wax alone has poor mechanical strength, it is more preferable to use it in combination with the E thermoplastic resin.

The method of impregnating the porous support with the thermoplastic resin includes a method of dissolving the resin in a suitable solvent and coating it to impregnate it, a method of hot melting the resin and coating it to impregnate it, and a method of coating and impregnating the resin by melting the resin with heat, and a method of coating and impregnating the resin by dissolving the resin in a suitable solvent. There are no particular limitations on the method of coating the porous support before drying, and then peeling off the releasable base material, or the method of extrusion lamination.

An example of the method for producing base paper of the present invention will be explained with reference to FIG.

The porous support 1 is fed to a resin impregnation device. The resin impregnation device contains a resin solution 11 dissolved in a suitable solvent, through which the porous support 1 is passed via several rolls 12 and then in a drying oven 10. The solvent is evaporated to obtain the base paper 8 of the present invention.

Here, the amount of resin impregnated is suitably about 4 to 60 g/lrr; if the amount is too small, defects will occur as a membrane, while if it is too large, the perforation sensitivity will decrease.

The thickness of the heat-sensitive mimeograph base paper of the present invention obtained as described above is generally 10 to 80 tLm, the tensile strength is 10 Kg/crn" or more, and the elongation is preferably about 0 to 100%. The smoother the surface of the base paper, the better 1
In the case of the base paper of the present invention, calendering treatment or the like may be applied to improve the surface smoothness.

In a preferred embodiment of the present invention, as shown in the first diagram, a resin absorber can be laminated on one side of the upper base paper, and in this way, a conventionally known plate-making device can be used as is. I can do it.

Further, the resin absorber used in the above embodiments and the plate-making method of the present invention may be any material that absorbs the resin melted in the base paper. For example, the porous support as described above may be used as it is. I can do it.

The heat-sensitive mimeograph base paper of the present invention as described above has excellent plate-making properties, but when forming a mimeograph hole by heating the base paper with a thermal head or other method, the thermal head may fuse to the base paper depending on the conditions. This may destroy the thermoplastic resin film layer.

In order to solve this problem, it is preferable to form a thermal adhesion prevention layer made of silicone oil, silicone resin, surfactant, or these and a binder resin on one side of the base paper.

The heat fusion prevention layer may be formed by dissolving or dispersing necessary materials in an organic solvent or water to prepare a coating solution, and applying this to the eyebrow surface of the thermoplastic resin film by any method. The thickness of the heat fusion prevention layer is preferably thin, since if it is too thick, the heat sensitivity will be reduced and the formation of perforations will be insufficient, and for example, a thickness of about 0.1 to 10 μm is preferable.

An example of a plate-making method using the heat-sensitive mimeograph base paper of the present invention will be explained with reference to FIG. 3.

The base paper 8 is supplied from a winding roll onto a platen roll 7 on which an endless resin absorbent belt 6 is wound, and is stacked thereon, and the thermal l bed 4 is brought into contact with the back surface of the base paper 8 in accordance with an image signal. The area of the base paper 8 that is in contact with the thermal head 4 is heated, and the resin impregnated into the support is melted. The molten resin is absorbed into the resin absorber belt 6 by capillary action, and most of the molten resin is transferred to the belt.

At one end of the resin absorber belt 6, the absorbed resin is removed by a resin recovery device 9 such as a tank containing a solvent, and the belt is dried through a drying oven 10 and returned to the platen position for circulation use. Of course, to simplify the plate-making apparatus, the resin recovery device and dryer may be omitted, and the resin absorbent belt may be replaced after a certain amount has been used.

(Example) Next, the present invention will be described in more detail with reference to Examples. In the text, parts or percentages are based on weight unless otherwise specified.

Example 1 Polyethylene wax (Polytail H1 manufactured by Mitsubishi Kasei Corporation) 80 mm was applied to a 300 mesh sheet made of polyamide fiber.
part and polyester resin (Byron 600, manufactured by Toyobo ■)
A mimeograph base paper of the present invention was obtained by melting a mixture consisting of 20 parts and impregnating it at a rate of 20 g/d.

On the other hand, as a thermoplastic resin absorber, a porous thin paper made of hemp with a thickness of 40 μm and a basis weight of 10 g/m' was superimposed on the above base paper, and plate-making was performed using the thermal head of Recovort 5S950, after which the absorber was removed. Printing was carried out. As a result, printed matter with extremely excellent image quality and no white spots was obtained.

(Effects) According to the present invention as described above, it is possible to obtain a heat-sensitive mimeograph base paper on which perforation can be performed accurately, thereby making it possible to print with high image quality.

[Brief explanation of drawings]

FIG. 1 is a diagram for schematically explaining the thermal mimeograph base paper of the present invention, FIG. 2 is a diagram for schematically explaining an example of manufacturing the mimeograph base paper of the present invention, and FIG. 3 is a diagram for explaining the method of the present invention. It is a figure explaining diagrammatically. 1: Porous support 2: Thermoplastic resin 3: Resin absorber 4: Thermal head 5; Perforation 6: Resin absorber belt 7: Platen roll 8: Base paper 9: Resin recovery device 10: Drying oven 11: Resin solution 12 ;Roll Figure 2 Figure 3

Claims (3)

[Claims] (1) A heat-sensitive mimeograph base paper characterized by having a porous support impregnated with a thermoplastic resin. (2) The thermal mimeograph base paper according to claim 1, comprising a resin absorbent layer laminated on one side of a resin-impregnated support. (3) Heat-sensitive mimeograph base paper made of a porous support impregnated with a thermoplastic resin, a resin absorbent layer layered on one side of the base paper, and the other side of the base paper selectively heated in an imagewise manner. 1. A method for making a plate for thermal mimeograph base paper, which comprises melting an impregnating resin and absorbing the molten resin into a resin absorber.